"[1] In the civil wars of the reign of Urraca (1109–26), he favoured her son, the future Alfonso VII (1126–57),[2] and is counted among the Galician leaders of the latter's cause, with Diego Gelmírez and Pedro Fróilaz de Traba.
[7] The first record of Gómez dates from March 1110, when he held the fortress of São Cristóvão (Felgueiras) on behalf of Henry, Count of Portugal.
[13][14] It is unknown if Gómez was present at Ricobayo for the negotiations with the Portuguese, but by the resultant treaty Theresa and Fernando lost control of Tui, Ourense, and other districts north of the Minho.
[15] When Gómez's uncle, a certain Count Fernando died sometime before 1126, half of the monastery of San Salvador de Budiño (Botinio), which had belonged to their family since its foundation at an unknown date, escheated to the crown in accordance with a judicial ruling.
On 26 July the brothers—with Gómez owning three quarters—donated the whole monastery, with all the churches and lands it possessed, to the Benedictine Abbey of Cluny, a longtime ally of the Leonese monarchy.
[16] Although the charter by which Alfonso restored half of the monastery to the Núñez brothers is lost, the king confirmed the donation by a royal privilege of August 1142, at the request of Peter the Venerable, the Cluniac abbot then visiting Spain.
[18] While the Chronica Adefonsi imperatoris (book I, §74) reports that he joined Rodrigo Pérez de Traba in revolt against Alfonso in 1136, in support of the Portuguese and Navarrese, who contrived to invade León–Castile simultaneously from both sides.
[20] Also in 1138 Gómez made a donation to Celanova, a large and influential Benedictine house in Galicia, and his wealth and power at the time are indicated by the presence of three clerici (clerics) at his court, serving as chaplains and secretaries.
[21] Gómez had been a loyal supporter, though only an occasional courtier, of Alfonso VII from 1126, but sometime between 1138 and 1140 he changed his allegiance to Afonso Henriques, the son of Henry of Portugal.
Comes Gomez Nunii, ut cognovit se esse reum, verecundatus est, et transiens fugiendo montes Pirineos, vellet nollet, quia non erat ei locus ad habitandum, fecit se monachus in monasterio Cluniacensi.The King [of Portugal] discharged Counts Rodrigo and Núñez from his service because they had caused discord between himself and the Emperor.